CHRISTOPHERSEN — Argentina's Adecoagro, an industrial farming multinational has turned one of its dairy farms into a surprising source of power. A new technique for generating energy from cow dung has now proven to supply enough electricity from cowpat to power a town of 5,000 residents. Its biodigester system with a 1.4 MW capacity, began operating in November in its state-of-the-art sheds in Christophersen in the province of Santa Fe, west of Buenos Aires.

The system was hailed last month by Argentine Minister of Agriculture Luis Miguel Etchevehere, who described the generator as "absolutely revolutionary" for its size and innovation. The farm is already a model of progressive dairy farming. Its 7,000 cows are described as living in comfort and with minimal stress in large, air conditioned sheds where they are fed, sleep on sand beds, enjoy automatic cleaning systems. Surrounding land, located in the heart of the muggy pampas, is used to grow feed crops for them.

These conditions have helped raise milk yields that have reached 37 liters a day, compared to the national average of 18 liters. Milking takes place on conveyor belts that can hold 80 cows at once, and lasts eight minutes. The farm thus milks 500 cows an hour over seven hours a day, producing 250,000 liters of milk a day.

Its only glitch was what to do with the effluents produced by these happy cows, which reportedly poop where they please, from pathways to their sand beds, requiring constant cleaning. The firm decided to use an Energy Ministry program, Renov.Ar, from 2016, to turn this waste into power.

The cowpat is separated from the sand and continually sent into three, large hermetically sealed tanks (the biodigesters). There "methanizing" bacteria act on them to produce methane gas that feeds a big generator. The Italian-designed technology came at a cost of $6 million. The firm is making plans to double the dairy farm to hold 14,000 cows. Adecoagro also produces ethanol from sugarcane in its Brazilian operations.

See more from Tech / Science here